fragment_one.xml

<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".ui.FragmentOne">

    <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appbar_fragment_one"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/AppTheme.AppBarOverlay"
            app:layout_constraintTop_toTopOf="parent">

        <androidx.appcompat.widget.Toolbar
                android:id="@+id/toolbar_fragment_one"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:title="@string/fragment_one"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

    </com.google.android.material.appbar.AppBarLayout>

    <Button
            android:id="@+id/go_to_fragment_two"
            android:layout_width="196dp"
            android:layout_height="wrap_content"
            android:text="@string/go_to_fragment_two"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintBottom_toBottomOf="parent" />

    <Button
            android:id="@+id/finish_app"
            android:layout_width="196dp"
            android:layout_height="wrap_content"
            android:text="@string/finish_app"
            app:layout_constraintTop_toBottomOf="@id/go_to_fragment_two"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintLeft_toLeftOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>